#include<iostream>
#include<vector>
#include<queue>
#include<cstring>
#include<cmath>
#include<map>
#include<set>
#include<cstdio>
#include<algorithm>
#define debug(a) cout<<#a<<"="<<a<<endl;
using namespace std;
const int maxn=1e5+1000;
typedef long long LL;
inline LL read(){LL x=0,f=1;char ch=getchar();	while (!isdigit(ch)){if (ch=='-') f=-1;ch=getchar();}while (isdigit(ch)){x=x*10+ch-48;ch=getchar();}
return x*f;}
vector<int> findOriginalArray(vector<int>& c) {
    if(c.size()&1) return vector<int>();
    multiset<int>s;
    for(int i=0;i<c.size();i++) s.insert(c[i]);
    vector<int>a;
    while(s.size())
    {
        int num=*s.begin();
        a.push_back(num);
        s.erase(s.begin());
        if(s.find(num*2)!=s.end())
        {
            s.erase(s.find(num*2));
        }
        else return vector<int>();
    }
    return a;
}
int main(void){


   	return 0;
}
